docs: Add crate documentation metadata to Cargo.toml

Author: zurawiki

Cargo.toml

@@ -12,6 +12,7 @@ keywords = ["openai", "ai", "gpt", "bpe"]
 readme = "./README.md"
 homepage = "https://github.com/zurawiki/tiktoken-rs"
 repository = "https://github.com/zurawiki/tiktoken-rs"
+documentation = "https://docs.rs/crate/tiktoken-rs/"
 license = "MIT"
 [profile.release]
 incremental = true

tiktoken-rs/Cargo.toml

@@ -9,6 +9,7 @@ keywords.workspace = true
 authors.workspace = true
 homepage.workspace = true
 repository.workspace = true
+documentation.workspace = true
 license.workspace = true
 readme = "../README.md"